Preparation of coloring-matters for luster-ware.



STATES UNlTE PATENT OFFICE.

GEORG ALEFELD, OF DARMSTADT, GERMANY, ASSIGNOR TO LUDWIG ZIEGENBRUCI-l,OF DARMSTADT, GERMANY.

PREPARATlON OF COLORING-MATTERS FOR LUSTER-WARE.

SEEGLFIZGATIGII forming part of Letters Patent No. 686,695, datedNovember 19, 1901.

Application filed June 1, 1900. Serial No. 18,771. (No specimens.)

To all whom it may concern.-

Be it known that I, GEORG ALEFELD, a subject of the Emperor of Germany,and a resident of Darmstadt, Germany, have invented certain'new anduseful Improvements in the Preparation of Coloring-Matters for Luster-Ware, of which the following is a specification.

In the production of pigments, coloringmatters, or lusters for or onporcelain, glass, enamel, or the like, according to this invention,solutions of boracic-acid-yielding materials are employed, which afterhaving been applied to porcelain, glass,or the like by firing or bakingleave behind boracio acid. As boraoic-acid-yielding materials allboracio-acid others may be employed, Whether obtained from boron chloridand alcohol, from borax with ether sulfate, or in any other manner. Forexample, they can be conveniently obtained by heating isobutyl alcoholwith fused boracic acid. At about 250 oentigrade there remains behind. athick or semiliquid residue which will dissolve in or mix with etherealoils in any proportion. If these boracic solutions be added to pigmentsor glazes used in producing luster-ware, either by themselves or incombination with lusters of precious metals, borates will form afterfiring in the place of the metal coatings and will produce their effectupon the metallic oxide or the precious metals, as the case may be.

Lusters may be defined as solutions of metal resinates in ethereal oils,and they have heretofore been used for coating porcelain, glass, or thelike with a very fine layer of metal to give color to the materialcoated. This layer is so fine that the real color of the metal itself isnot perceptible, but the surface coated takes on singular, mutable, andshining colors. By preparing these lusters in combination, as abovedescribed, very beautiful coloring elfects are obtained, which are notproduced by simple lusters.

Thus

cobalt luster combined with the solution con taining boracic acid willgive a beautiful blue color upon enamel, while solutions containinggold, such as gold luster, will, according to the proportion of puregold, impart purple, deep red, or rose-pink colors to glass or the like.

I claim 1. The process herein described of preparing pigments orcoloring-matters for glass, enamel or the like, which consists in addingboracic-acid-yielding materials to lusters of the metals.

2. The process herein described of preparing pigments orcoloring-matters for glass, enamel or the like, which consists in addingboracic-acid-yielding materials to lusters of the precious metals.

3. The process herein described of preparing pigments orcoloring-matters for glass, enamel or the like, which consists in addingboracio-acid others to lusters of the metals.

4. The process herein described of proper ing pigments orcoloring-matters for glass, enamel or the like, which consists in addingboracic-acid ethers to solutions of metal resinates in ethereal oils.

5. The process herein described of preparing pigments orcoloring-matters for glass, enamel or the like, which consists in addinga boracic-acid solution to a luster of the procious metals.

6. The process herein described of preparing pigments orcoloring-matters for glass, enamel or the like, which consists in addinga boracic-acid solution to gold luster.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORG ALEFELD.

Witnesses:

FRANZ IIASSLACHER, MICHAEL VOLK.

